When using powder metallurgy to produce a composite material having aluminum as the matrix phase, ceramic particles of Al2O3, SiC or B4C, BN, aluminum nitride and silicon nitride are mixed as reinforcing materials into an aluminum powder which forms the matrix phase, then this mixed powder is loaded into a can and cold-pressed or the like, then degassed or sintered to form the desired shape. Sintering methods include methods of simply heating, methods of heating while compressing such as hot-pressing, methods of pressure sintering by hot plastic working such as hot extrusion, hot forging and hot rolling, methods of sintering by passing electricity while compressing, and combinations of these methods. Additionally, the sintering can be performed together with the degassing.    Patent Document 1: JP 2001-329302 A